CVE-2026-11331CWE-790

Potential wildcard CNAME RPZ policy bypass

High · published July 22, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
35.9
In the wild
Unconfirmed
What it is

An attacker who knows (or guesses) that a resolver uses RPZ with wildcard CNAME policies can craft query names long enough to trigger a NAMETOOLONG error condition during RPZ processing. This is not handled correctly and may lead to defeating the RPZ rule. It also may lead to an unexpected exit of the BIND 9 software.

This issue affects BIND 9 versions 9.16.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.16.8-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00428 · 35.9th percentile
Weakness
CWE-790 · Improper Filtering of Special Elements
Published
2026-07-22T14:10Z
EPSS history
Timeline
  • 22 JUL 14:10Z
    Potential wildcard CNAME RPZ policy bypass
    cvelistv5